Windows Phone 7 SDK here; YouTube, Netflix demoed; no CDMA yet

Windows Phone 7's final SDK has been released, and a range of third-party …

Two weeks after the operating system itself was finalized, Microsoft has released the Windows Phone 7 SDK to developers. Applications developed with the new SDK will be submittable to the Windows Phone Marketplace when that opens for submissions next month.

The new SDK brings many welcome improvements; it (finally) includes built-in support to allow developers to offer many of the same interface concepts as the built-in phone software uses. Specifically, Panoramas, used in the various hubs such as People and Office, and Pivots, used in the e-mail client, are now available for all to use. The sideways-scrolling panoramas in particular are a striking part of the Windows Phone 7 experience, and their absence led many to attempt to develop their own versions. Having a standard control to use will ease development and provide greater uniformity in third-party applications.

In spite of these additions, the SDK still isn't complete. There are desirable things that the built-in applications include—such as picking dates and times—that aren't available to third parties. In spite of the work that Microsoft has put in to Windows Phone 7 over the last few months of public releases, it's still a new platform that's immature in many ways.

To fill some of these gaps, the company is using its open source Silverlight Toolkit project to provide unsupported alternatives to the missing functionality.

In addition to the main SDK, Microsoft also released a Mobile Advertising SDK. Microsoft already has its own advertising platform, used in Bing (and soon Yahoo!), and unsurprisingly, it's bringing it to its mobile platform—for some months, Redmond has been promoting its phone operating system as an "ad-serving machine." With the SDK, it's trivial for developers to add advertising to their applications as a way of monetizing them.

Initially, the ads will only be available in the US, to US developers. Support in other markets will begin rolling out early next year. With Windows Phone 7 launching first in Europe, this is a little surprising. Microsoft already sells ads outside the US, and can pay non-US developers of phone apps, so on the face of it, it would seem that all the legal hurdles have been jumped, giving little reason for such a restriction. The first ads will be plain text and image banners, with rich media ads—similar to those of Apple's iAd—promised for the future. Microsoft's ads will pay out 70 percent of ad revenue to the application publisher, in contrast to iAd's 60 percent.

Along with the new SDKs, some new applications and capabilities have been demonstrated; among others, there's a good-looking Netflix app with streaming video, and an official Twitter app.

In a Bieber-heavy demo, Microsoft's Brandon Watson also showed off Windows Phone 7's YouTube support. Surprisingly, this used neither a YouTube application nor Flash (which is not available on the platform at the moment). Instead, Windows Phone 7 streamed the videos directly from YouTube using YouTube's APIs for that purpose; the support is built-in. YouTube videos also appear to integrate into the operating system's hubs, putting them on an equal footing with videos stored on the device itself.

A couple of videos apparently showing HTC's custom software for the phone have also surfaced. Perhaps disappointingly, unlike many of the other third-party applications that are being shown off, they appear to totally disregard the whole Windows Phone 7 look-and-feel, instead sticking with HTC's own Sense styling as already used on Android and Windows Mobile devices.

Building its own UIs has served HTC well with those OSes, but it's not so clear that it will be a winning strategy on Microsoft's new platform; the stylistic differences between the built-in software and HTC's is quite jarring.

It has also emerged that neither Verizon nor Sprint will have Windows Phone 7 devices on launch day. The reason? CDMA devices won't be supported until next year. Microsoft says the decision, as with so much of the new operating system, was driven by a question of choosing what to concentrate on; better to focus on a few areas and deliver a high quality product than spread the effort and reduce the quality.

What's not immediately clear is the differences between CDMA and GSM that would be relevant; CDMA does introduce some issues not found in GSM handsets—GSM handsets can perform simultaneous voice and data calls, CDMA usually cannot—which might be the reason. Or it might simply be the case of wanting to ensure that the phones are well-tested and debugged: as such, working on phones that can sell globally is a better use of resources than working on handsets that are only of use in the US and a few other limited markets.

This may be missing a trick—getting to Verizon before Apple would surely be a good thing for Microsoft—but on the other hand, both iPhone and Android gained traction in the market without supporting the CDMA carriers from day one. Microsoft will be no different: Verizon availability is not enough to elevate a platform to greatness, and lack thereof is not enough to doom a platform to failure.